This is implementation of the Modulated Complex Lapped Transform by H. Malvar that I hacked together, similar to FFT, this discrete mathematical algorithm is used in similar fashion in the field of digital signal processing.
License: FREEWARE for commerical and non-commercial use, but would appreciate a mention in credits
See: https://en.wikipedia.org/wiki/Modulated_complex_lapped_transform
It works! and it is 1:1 implementation of the algorithm described in the Malvar's article.